Circuit breaker with adjustable thermal and magnetic controls



T. M. COLE CIRCUIT BREAKER WITH ADJUSTABLE March 23, 1954 THERMAL ANDMAGNETIC CONTROLS 2 Shegts-Sheet 1 Filed April 17, 1952 F/Lii.

} INVENTOR. 77/0444; M. (01.5 66 BY WM JrfaK E/J March 23, 1954 E2,673,264

' CIRCUIT BREAKER WITH ADJUSTABLE THERMAL AND MAGNETIC CONTROLS 'F'iledApril 17, 1952 2 Sheets-Sheet 2 9 I (0' l g 36 K 7 /42 BY 5% fiAWL' F M7 lrroewsKs Patented Mar. 23, 1954 CIRCUIT BREAKER WITH ADJUSTABLETHERMAL MAGNETICCQNTROLS Thomasv M. Cole,i Ha rrison, N. assignor toFederal Electric Products Gompany, Newark, N. J a corporation orDelaware Application April 17, 1952, Serial No, 282,819

This invention relates to circuit breakers in general'and, more:particularly, tocircuit break,- ers of the type which aremanuallyoperable to open. or to close'the circuit and automaticallyoperable to open the circuit upon. theoccurrence of' an overloadf orshort circuitcondition.

One object of the. present invention is the provision of acircuitbreaker having independently adjustable thermal and magnetic controlswhereby to provide for the accurate calibration of'the circuitbreaker;

v Another object of the present invention i the provision ofimprovedtripping means for an automatic circuit breaker. including a currentresponsive" bimetallic member adapted to effect opening ofthe'cir'cuit'breaker' upon moderate currentwoverload and magneticelements, for e'fiectingmagnetic-tripping of the circuit breakeron/heavy current overloads and short circuits.

Another object of the present invention is the provision of trippingmeans of the-above character' which. is'simple andeconomical tomanufacture'andefiectiveinoperation. l

i'Ihe above and other objects, features and advantages of the presentinvention will be more fully'understood from the following descriptionconsidered inconnection with the accompanying illustrativedrawings.

" In the'drawings:

Fig; lls a top plan view of a multi-pole circuit breaker 'according tothe present invention with the cover shownrremoved;

' Fig.2 isza secti nalview taken on the line 2-2 ofFig;1:;'

Fig; 3 is asectional view taken on the line 3'-3 Fig 1;

r Fig. 4 is a sectional view taken on the line 41-4 Fig. 5 isa sectionalview taken on the line 5 5 OfFigil; t a

. Fig.' 6 is a. perspective view of the trip bar;

Fig. 7 is a view similar to Fig. l of a s n pole circuit breakeraccording to the present invention; Fig: 8 is a sectional view taken on.theline fi.;8 of;Fig.7;-

Fig. 9 is a sectional view taken on the. line 9 -.9.of Fig. '7;

r, Fig. 10 is, a sectional view taken onithe, line |-lDofFig.7;

Fig. 11 isa perspectivev view ofthe trip bar of the circuit breakershown in Figs; 7-10; and

Fig. 12. is a. sectional view taken onthe line l 2-,---JTorrie.1'. 3'

j Rgefellflnggtfl the drawings; and; more particue 1 -Clai 1'ns. (01'.200 938) larly, toFigs. 1 through 6 thereof, there is shown a circuitbreaker of the multipole type, each pole comprisin a pair of terminalsl2 and- I4, one disposed at each end of the breaker. The circuit breakerIt includes a base It preferably of molded insulating material on whichthe several elements of'the breaker mechanism are mounted. A cover 18also preferably of molded insulating material is removably secured tothe base I6 and cooperates therewith to form an enclosing housing forthe breaker mechanism. The circuit breaker H] is also provided withassociated pairs of stationary contacts 20 and movablecontacts 22, andan arc extinguisher 24 of conventional construction. Each of the movablecontacts 22 is'mounted on-a movable contact member 26, said movablecontact members being movable to open and closed positions by theoperating mechanism. indicated generally at 28. Thus the commonoperating mechanism Z8 is provided for simultaneously actuating themovable contacts 22 to open-and to.closed positions, there beingprovided a. trip device indicated generally at 3il for effecting theautomatic opening of all of the movable contacts 22 in response topredetermined overload-conditions in the circuit through any pole ofthe-breaker. Each of the poles of the breaker is contained in. aseparate compartment formed by barriers 32 which extend for the lengthof the breaker. It Will be understood that the barriersv 32 are inalignment with similar barriers in the cover, [8- so that when the coveris in place theE barriers serve to insulate each compartment from anadjacent compartment. Each of the movable contact members is pivotallymounted intermediate its ends for movement by the common operatinmechanism indicated generally at 28. Said common: operating mechanismmay be of any -of the well-.knowntypes, for example, of the type shownin' Patent No. 2,419,125, issued Aprilr 15,1947, to I-Ieeler D. Dorfmanand Gerald J. Freese, for-Circuit Breaker.

The circuit breaker I0 is provided with an externally accessibleoperating handle 34 which is movable to open and closed positions formovingthe contact members. 26 to corresponding positions. Operativelyassociated with the operating mechanism 28- isa cradle36 having an endportion-38 Which-is operatively associated with the trip device; 30 in amanner to be described in detail hereinafter. Thetrip device comprisesatrip bar 40 having end shaft portions 42=which aremounted for rotationin the bearing portions 44 ofthe breaker. Thus theitrip bar is mountedfor. rctationr about its longitudinal axis and. is

3 transversely mounted in the breaker. It will be seen that the trip bar46 extends across the barrier 32, the latter being suitably recessed at46 for the reception of a central portion of the trip bar. The trip bar40 is provided with a laterally projecting portion 48 and a laterallydepending portion 56 for each compartment, said projecting and dependingportions being preferably formed integral with the trip bar. The tripbar 40 is notchedcentrally at 52, said notch being adapted to bepositioned on adjacent portions of barrier 32 at recess 46, the rotationof the trip bar in a counter-clockwise direction as viewed in Figs. 2and 3 being effective to release the cradle 36 for moving the contactmembers 26 to an open position. Positioned in each compartment is athermally responsive bimetallic element 54, said element being securedat one end to the conductor 56 in any well known manner. At the free endof the element 54 there is threadedly received screw member 58 having atone face portion 66 a protuberance 62, the latter bein adapted tocooperate with the laterally projecting portion 48 of the trip bar 46.It will be seen that the rotation of the screw member 58 will beeffective to axially move the latter whereby to vary the space betweenthe protuberance 62 and adjacent portions of the face 64 of itsassociated projectin portion 46. As previously noted, each compartmentis structurally and electrically similar and the operating mechanismdisposed in each compartment is similarly structurally similar, exceptthat one compartment will be provided with operating mechanism 26 forsimultaneously actuating the contact members 26, one of which isdisposed in each compartment. From the above, it will be seen that eachcompartment is provided with an element 54 and the space between theprotuberance 62 and the associated projecting portion 46 may readily beadjusted by rotating the screw 58. Thus the positioning of the adjustingscrew 58 will be effective to calibrate the position at which bar 46will be tripped in response to a predetermined current in the associatedcircuit. It will be understood that a predetermined current in thecircuit will be effective to flex the free end of element 54 towards thetrip bar 40 and that the degree of flexing required for tripping bar 43is adjusted by means of the axial positioning of the screw member 1 58.The element 54 is connected in series into its associated circuitwhereby said element will be current responsive on a predeterminedoverload to rotate the trip bar in a counter-clockwise position asviewed in Figs. 2 and 3 to thereby release all of the contact members 26simultaneously to an open position. The thermally responsive bimetallicelement is adapted to trip the bar 40 after a time delay onpredetermined overload conditions.

Adjustably secured to each of the depending portions 50 or trip bar 46is an armature 66 which comprises a plate of magnetic material which hasa face portion 66 in confronting position with the face 16 of the deending portion 50. The armature 66 is adapted for lateral movementrelative to the depending portion 56 by means of the adjusting screwelement 12, the rotation of the latter being effective to move armature66 inwardly and outwardly of the face 16 of the depending portion 50 toadjust the air gap in the instant apparatus, as will become apparentfrom the description which follows. Associated with each of thebimetallic elements 54, adjacent to the secured end thereof is amagnetic yoke 14 havin pole faces 16 in confronting relation relative tothe armature 66. The magnetic yoke 14 is secured to the conductor 56 inany conventional manner, as by means of the rivets 18. Thus the element54 and the magnetic yoke I4 are secured to the conductor 56 and saidyoke 14 is positioned so as to be magnetically energized in accordancewith the current in element 54. A previously pointed out, the element 54is connected in series in its associated circuit whereby the magneticyoke is similarly connected into said associated circuit. The air gapbetween the pole faces I6 of the magnetic yoke 14 and the armature 66 isadjusted by rotating the screw element I2, it being apparent that saidrotation of the screw element will be effective to vary the distancebetween the armature 66 and the magnetic yoke 14. The armature 66 isadapted to be attracted to the magnetic yoke 14, instantaneously onoverload currents of predetermined magnitude, said attraction beingeffective to rotate the trip bar 46 in a counter-clockwise direction asviewed in Figs. 2 and 3, to thereby release cradle 36 for simultaneouslyopening the contact members 26. The trip bar 46 is provided with a latchmember 60 having a latch portion 82 which is adapted to cooperate withthe portion 38 of cradle 36. With the cradle 36 in the latchingposition, as shown in Figs. 1, 2 and 6, the portion 36 will abut and berestrained against the underside of the latch portions 62. On overloadconditions in the circuit breaker the trip bar 46 will be rotated in acounterclockwise direction, as aforedescribed, whereby the portion 38 ofthe cradle 36 will be released for clockwise rotation about itspivot 84whereby the operating mechanism 28 will simultaneously open all of thecompanion contacts 20 and 22. More specifically, overload currents of apredetermined magnitude will instantly cause armature 66 to be attractedto the yoke 14 to thereby rotate the trip bar 46 in a counter-clockwisedirection, the rotation of said trip bar bein effective to unlatch thecradle 36. Similarly,

lesser overloads after a time delay will cause the element 54 to flextowards the trip bar 46, said flexing movement causing the member 58 tomove the projecting portion 48 whereby. to rotate the trip bar 43 in acounterclockwise direction, as aforedescribed, to thereby unlatch thelatch portion 82 from the cradle 36. From the above, it will be seenthat the screw member 58 for calibrating the thermal overload isindependent of the adjustment element 12 for calibrating the magneticoverload whereby the circuit breaker [0 may be accurately calibrated,

The trip bar 46 is biased in a clockwise direction, as viewed in Figs. 2and 3, by means ofthe spring 96 which is positioned in the recess 92 ofpartition 32, said spring having its end 94 operatively associated withthe face portion 96 of the trip bar 60 whereby said spring will producea biasing componentwhich will urge the trip bar 40 in the clockwisedirection aforedescribed. It will be noted that the biasin of'the tripbar 46 in a clockwise direction will tend to urge the latch member 66into a latched position whereby a positive overload condition isnecessary for retating the trip bar in a counterclockwise direction tounlatch the cradle 36.

The electrical circuit for each of the poles is essentially the same andextends from the terminal l 2 through the conductor 56 and thebimetallic element 54, through the flexible wire I06 and through thecontact member 26 having contact oneof aplurality of compartmentsdefinedby The operating :mechanism 28 the barrier. 32. includes ,aforkedoperatinglever, I114; a toggle l;0,6,:.cQmDri$ing a pai-rof links,over centering springsI08 and areleasable cradle 36control1ed bath t ip.dev e. .0, afor deseribed- Th to ink ar pi ta l eonn et d together b thekneelpin a d said' e e links o e a conventional manner whereby theoperating mechanism 28 is of the quick makeand break type. is here to benoted-that the operating mechanism 28 formsnO part of the presentinvention and accordingly onlya general description fofsaid operatingmechanism is herein made. Thetie bar I. I2 which extends across all ofthe polesof the breakerextends through a suitable aperture in thebarrier32, it being noted that each of the movable. contact members. 26is connectedito thetie barIIZ'whereby the rotation of said tie bar willbe effective to simultaneously actuate all of the movable contactmembers 26. Thetransversely extending tie bar I I2 is mounted forrotation in the. breaker II] in any desired manner and each of the,contact members 26 is secured thereto at. Spaced. points through theintermediationof thelinks, IIII, eachof said. links straddlingitsassociated movable contaot memberj'26. The movement of the operatinghandle or lever. 34/is effective to correspondingly actuate, each ofthemovable contact members 26 Simulta ou l a i h e -shine of. the. tribar 40in. response to a current overload in any poleof the trip devices30 willbe effectiveto. open all of the circuitsofthe breaker as will bereadily apparent. When the tr ip bar'4 0, islll latched in response to acurrent overload the cradle 36 will-snap to an unlatched position beingrotated in a clockwise direction about its pivot 84, due to the--action-ofthe-springs I08. Thus on the release ofthe-cradle36it willberotated'in a clockwise direction as viewed in Fig. 2-by the spring I08which will be tensioned with the cradle 38 inaa latching position.The-release of said'cradle will also result-in: the rotationof tiebar H2in a.-.counter.clockwise direction viewing Fig. 2

whereby;each of the contact members 26 securede dffi? nes i sn fie es revic the lever 341st rotated from its tripped position to its.extreme-counter-clockwise or on position, ,This movement-of the lever 3A is, transmittedtto the radlewto rotat said cradle in acounter-clockwise;idirection, theendqportion: 3B.

ofesaidl cradle; passing theolatch portion. 82. of

thezlatchomembert BI]atoe inten-engagewith -said- 3:4;w illlube at aposition; intermediate the on portion 82. Thus the movementof th'ecradle-3d,

will be effective to rock the trip bar 40 counterclockwise againstthe-biasing of spring slightly.

past its normal positionto thereby .relatch the cradle 36. After thecradle is so relatched the contacts can be closed manually by movingthelever 34 clockwise to its closed circuit position. Aspreviouslymentioned the operating mecha-.

nism-28 is preferably of thequick make and-break type in which thesprings I03 actuate-the toggle mechanism to make. and break thecircuit-with a positive snap action. The aforedescribedcircuit breakeris trip-free sothat it is operative automatically in response topredetermined abnormal circuit conditions in any one of the polesthereofirrespective ofthe position of the-operating lever 34. takes place inany of the'poles of the circuit breakerlb the trip bar 40 will releasethecradle:

36 whereby each of thecontact-members 26 will be opened withasnap-action. Anarc extinguisher 2 is provided for each pole of thebreaker Al-.' though the circuit breaker I0. is-of the=two-po1e-.

and isgenerally of the spaced plate type.

type it will be understoodthat the trip device 30 of the presentinvention is equally applicable to a single-pole circuit breaker aswelllas to a multi-pole circuit breaker havingany numberof polespositioned in side-by-side-arrangedcome partments. Thus the trip-bar:40aforedescribed is equally applicable to- -a circuit: breaker having:-

any number of poles. With-reference tonEigs. :7 through 11 there isshown-asingle-pole circuit breaker I0 which is structurally similar tocircuit breaker Hl except that circuit breaker-I0" is of a single-poletype. The-circuit breaker I0 is provided with internal:structurewhich-is-substantially identical with the structure disposedinbreaker it exceptfor the trip bar 40' now to be described. The trip bar.40 is provided with. a laterally projecting portion 48 Whichis. op-

eratively associated with the cradle 36' in the manner described inreference to breaker III.

The latch member I26 is adaptedto perform the. same function as latchmember fill-of. breaker I0 and comprises a plate i22 which-is aperturedat,

I24 for the reception of the portion.38' of the cradle 36. Thus trip bar43 is structurally similar to trip bar' lfl except for the latch member.

I20 which is provided with aperture I24: through which extends theportion 38 of-cradle.36 in th latched position of the latter. It willbeapparent from the above that the rotation of trip. bar '40: inresponse tov an overload current conditionwill be effective: to releasethe cradle -38-for.c1ockwise rotation in the manner described above.Thus trip bar. 40 differs from trip bar; II].v in the latch member whichis operatively associated with the cradle 36. It will be seen fromtheabove that the trip bar 40 is integrated with there-- mainder of themechanism of breaker I0 in the An overload'condition in breaker III willcausethe-trip bar- 40 to rotate in a counter-clockwise directionwherebythe. face I32-will assume the- Thus if an overloadconditionposition I32 shown in Fig. 9. It is to be noted that thecomponent of force produced by the curved end portion I30 of spring 128is to the left of a line drawn from the center of the tri bar to thepoint of contact of the spring and face i152 whereby the trip bar willbe normally springurged in a clockwise direction. Thus, except for thespecific structural details afore-described circuit breaker I operatesin a similar manner to the circuit breaker I0 whereby it will be seenthat trip device 30 according to the present invention is applicable toa single pole breaker as well as to a multi-pole circuit breaker It willbe seen from the above that the trip device 30 according to the presentinvention provides for thermal and magnetic overload controls which areeach individually adjustable to actuate a common trip bar whereby toprovide a circuit breaker which may be readily calibrated with a highdegree of accuracy.

In order to apply contact pressure to the movable contact member 26 whenthe latter is closed, there is provided means for biasing said contactmember in a clockwise direction, as viewed in Fig. 12. Moreparticularly, the link member H4, which straddles the contact member 26,has an intermediate portion of said contact member pivotally mountedthereon by means of the pivot pin I40. As previously pointed out, linkmember H4 is secured to the tie bar H2 in any conventional manner, as byhaving said tie bar passed through a complementary aperture in said linkmember. The tie bar H2 is also provided with a strap element I46 whichis secured to the bottom plate I48 of the link member i it in anysuitable manner, said element being efiective to rigidly secure togetherthe tie bar and said link member. Secured to the bottom plate M3 in anysuitable manner is a plate member 652, said plate member having an endportion i54 which is operatively associated with portion Hit of member26 to limit the pivotal movement of the latter member in a clockwisedirection when the member 26 is in an open circuit condition. It is tobe noted that the link member H 4 adjacent to its securement to the tiebar II2 is U-shaped in cross section and is provided with a base plateI48 which is adapted to receive spring I44 positioned between said baseplate and the end portion I42 of the contact member 26. The contactmember 26 is further provided with an integral extension I50 which isreceived in spring I44 for restraining said spring in position. Thespring I44 is positioned as aforedescribed under tension whereby thecontact member 26 will be spring urged in a circuit closing directionabout its pivotal mounting Mil. Thus when the tie bar H2 is rotated in acircuit closing direction by the operating mechanism aforedescribed, thelink member H4 will be com comitantly rotated to thereby move themovable contact member 26 in a circuit closing direction with the springI44, applying contact pressure to said movable contact member when thelatter is in a circuit closed condition. Thus the compression springI44, which is associated with the contact member 26 in the manneraforedescribed, will apply a contact pressure between the companioncontacts 20 and. 22 when the latter are in a circuit closed condition.It will be understood that each of the movable contact members 26 isstructurally similar and is integrated with its tie bar H2 in astructurally similar manner.

ferred embodiments of my invention, it will be understood that variouschanges may be made in the present invention without departing fro..."

the underlying idea or principles of the invention within the scope ofthe appended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent is: 1. In a circuit breaker having stationary and movablecontact members, mechanism for actuating said movable contact member toopen and close the circuit breaker, and a trip device including amovable latching member for releasably holding said mechanism incontact-closing condition, control means for said trip device,comprising a bimetallic strip responsive to the current in the circuit,an adjustable member carried by said strip and operable to move withsaid latching member to a mechanism-releasing position in response toflexing of said strip when the current reaches a predetermined value foropening the circuit breaker, electro-magnetic means operable to movesaid latching member to a mechanism-releasing position when the currentreaches a predetermined value, said electromagnetic means including amagnetic yoke disposed relative to said strip for energization by thecurrent therein and an armature operatively connected to said latchingmember, and means operable independently of the strip for adjusting theair gap between said yoke and said armature.

2. In a circuit breaker having stationary and movable contact members,mechanism for actuating said movable contact member to open and closethe circuit breaker, and a trip device including a movable latchingmember for releasably holding said mechanism in contact-closingcondition, control means for said trip device, comprising a bimetallicstrip responsive to the current in the circuit, an adjustable membercarried by said strip and operable to move with said latching member toa mechanism-releasing posi- 'tion in response to flexing of said stripwhen the current reaches a predetermined value for opening the circuitbreaker, electro-magnetic means operable to move said latching member toa mechanism-releasing position when the current reaches a predeterminedvalue, said electro-magnetic means including a magnetic yoke disposedrelative to said strip and energized by the current therein and anarmature carried by said latching member and adjustably movable thereonin relation to said magnetic yoke for adjusting the air gap between saidyoke and armature.

3. In a circuit breaker having stationary and movable contact members,mechanism for actuating said movable contact member to open and closethe circuit breaker, and a trip device including a movable latchingmember for releasably holding said mechanism in contact-closingcondition, control means for said trip device, comprising a bimetallicstrip responsive to the current in the circuit, a member actuated bysaid strip and operable to move said latching member for moving thelatter to a mechanism-releasing position in response to flexing of saidstrip when the current reaches a predetermined value for opening thecircuit breaker, electro-magnetic means operable to move said latchingmember to a mechanism-releasing position when the current reaches apredetermined value, said electro-magnetic means including a magneticyoke disposed relative to said strip and for energization by the currenttherein and an armature carried by said latching member and adjustablymovable there- 9. on in relation to said magnetic yoke for adjustingtheair gap between said yoke and armature.

4; In a circuit breaker having stationary and movable contact members,mechanism for actuating said movable contact member to open and closethe circuit breaker, a trip device including a movable latching memberfor releasably holding said mechanism in contact-closing condition,control means for said trip device, comprising a bimetallic stripresponsive to the current in the circuit, said strip being fixed at oneend thereof and free to flex at its opposite end, said latching memberbeing mounted independently of said strip, an adjustable screw membercarried by said free end of the strip and operable upon said latchingmember for moving the latter to a mechanism-releasing position inresponse to flexing of said strip when the current reaches apredetermined value for opening the circuit breaker, electrc-iiagneticmeans operable to'move said latching member to a mechanismreleasingposition when the current reaches a predetermined value, saidelectro-magnetic means including a magnetic yoke disposed relative tosaid strip for energization by the current therein and an armaturecarried by said latching member and adjustably movable thereon inrelation to said magnetic yoke for adjusting the air gap between saidyoke and armature.

5. In a circuit breaker having stationary and movable contact members,mechanism for actuating said movable contact member to open and closethe circuit breaker, and a trip device including a movable latchingmember for releas ably holding said mechanism in contact-closingcondition, control means for said trip device, comprisingthermal-current means and magnetic means individually responsive to thecurrent in the circuit for individually actuating said latching memberto mechanism-releasing position, in response to different currentvalues, respectively, and including individually adjustable membersoperable individually by said thermal current means and by said magneticmeans, respectively, for adjusting the response of said latching memberin relation to the current values.

6. In a circuit breaker having stationary and movable contact members,mechanism for actuating said movable contact member to open and closethe circuit breaker, and a trip device including a movable latchingmember for releasably holding said mechanism in contact-closingcondition, control means for said trip device, comprisingthermal-current means and magnetic means individually responsive to thecurrent in the circuit for individually actuating said latching memberto mechanism-releasing position, in response to different currentvalues, respectively, and including individually adjustable membersoperable individually by said thermal current means and by said magneticmeans, respectively, for adjusting the response of said latching memherin relation to the current values, said latching member including a tripbar mounted for pivotal movement about its own axis and having actuatingarms disposed at opposite sides of said axis for turning the bar, one ofsaid individually adjustable members being mounted on one of said armsand the other of said adjustable members being operable to movethe otherof said arms.

7. In a circuit breaker having stationary and movable contact members,mechanism for actuating said movable contact member to open and closethe circuit breaker, and a trip device lb including a movable latchingmember for releasably holding said mechanism in contact-closingcondition, control means for said trip device, comprisingthermal-current means and magnetic means individually responsive to thecurrent in the circuit for individually actuating said latch- 7 ingmember to mechanism-releasing position, in

response to diilerent current values, respectively, and includingindividually adjustable members operable individually by said thermalcurrent means and by said magnetic means, respectively, for adjustingthe response of said latching memher in relation to the current values,said latching member including a trip bar mounted for pivotal movementabout its own axis and having actuating arms disposed at opposite sidesof said axis for turning the bar, one of said individually adjustablemembers being mounted on one of said arms and the other of saidadjustable members being operable to move the other of said arms, saidthermal-current means including a bimetallic strip on which said otherof the adjustable members is mounted and which flexes toward said otherarm, in response to a predetermined current value, for operating saidarm to move said latching member to mechanismreleasing position.

8. In a circuit breaker having stationary and movable contact members,mechanism for actuating said movable contact member to open and closethe circuit breaker, and a trip device including a movable latchingmember for releasably holding said mechanism in contact-closingcondition, control means for said trip device, comprisingthermal-current means and magnetic means individually responsive to thecurrent in the circuit for individually actuating said latching memberto mechanism-releasing position, in response to different currentvalues, respectively, and including individually adjustable membersoperable individually by said thermal current means and by said magneticmeans, respectively, for adjusting the response of said latching memberin relation to the current values, said latching member including a tripbar mounted for pivotal movement about its own axis and having actuatingarms disposed at opposite sides of said axis for turning the bar, one ofsaid individually adjustable members being operable to move one of saidarms and the other of said adjustable members being operable to move theother of said arms, said individually adjustable members beingpositioned in relation to said arms, respectively, so that both armsmove in the same rotary direction when operated by said individualmembers, respectively.

9. In a circuit breaker having stationary and movable contact members,mechanism for actuating said movable contact member to open and closethe circuit breaker, and a trip device including a movable latchingmember for releasably holding said mechanism in contact-closingcondition, control means for said trip device, comprisingthermal-current means and magnetic means individually responsive to thecurrent in the circuit for individually actuating said latching membarto mechanism-releasing position, in response to different currentvalues, respectively, and including individually adjustable membersoperable individually by said thermal current means and by said magneticmeans, respectively, for adjustting the response of said latching memberin relation to the current values, said latching member including a tripbar mounted for pivotal movement about its own axis and having actuatingarms disposed at opposite sides of said axis for turning the bar, one ofsaid individually adjustable members being operable to move one of saidarms and the other of said adjustable members being operable to move theotherol said arms, said individually adjustable members being positionedin relation to said arms, respectively, so that both arms move in thesame rotary direction when operated by said individual members,respectively, said thermal-current means including a bimetallic striparranged to be responsive to the current in the circuit controlled bythe circuit breaker, and said magnetic means including a magnetic yokeenergized by the current in said strip.

10. In a circuit breaker having stationary and movable contact members,mechanism for actuating said movable contact member to open and closethe circuit breaker, and a trip device including a movable latchingmember for releasably holding said mechanism in contact-closingcondition, control means for said trip device, comprisingthermal-current means and magnetic means individually responsive to thecurrent in the circuit for individually actuating said latching memberto mechanism-releasing position, in response to different currentvalues, respectively, and including individually adjustable membersoperable individually by said thermal current means and by said ma neticmeans, res ectively, for adjusting the response of said latching memberin relation to the current values, said latching member including a tripbar mounted for pivotal movement about its own axis and having actuatingarms disposed at o posite sides of said axis for turning the bar, one ofsaid individually adjustable membe s bein operable to m ve one of saidarms and the other of said ad ustable members being operable to move theother of said arms. said individually adiustable members beingpositioned in relation to said arms, respectively, so that both armsmove in the same direction when ope ated, by aid in v ua m rs.respectively. said thermal-current means includine a bimeta lic striparranged to be res onsive to the current in the circuit controlled bythe circuit breaker. and said ma netic means includin a magnetic yokeener ized by the current in said strippone of said ad ustable membershaving an armature carr ed thereby in position to be attracted by saidma netic yoke when the current in the strip reaches a predeterminedvalue.

11.. In a circuit breaker havin stationary and movable contact members.mechanism for actuating said movable contact member to open and closethe circuit breaker. and a trip device ncluda movable latching memberfor releasably holdin said mechanism in contact-closing condition,control means for said trio device, comprising thermal-current means andma netic means individually res onsive to the current in the circuit forindividually actuat n said latchin member to mechanism-releasingposition. in response to different current values, respectively, andincluding individually ad ustable members operable individually by saidthermal current means and by said magnetic means, respectively, foradjust ing the response of said latching member in relation to thecurrent values, said latching member including a trip bar mounted forpivotal movement about its own axis and having actuating arms disposedat opposite sides of said axis for turning the bar, one of saidindividually adjustable members being operable to move one of said armsand the other of said adjustable, members 12 being operable to move theother of said arms, said individually adjustable members beingpositioned in relation to said arms, respectively, so that both armsmove in the same rotary direction when operated by said individualmembers, respectively, said thermal-current means including a bimetallicstrip having its low expansion side facing said trip bar so as to flextoward the latter when heated for actuating one of said individuallyadjustable members for operating one of said arms, and said magneticmeans including a magnetic yoke facing toward the other of saidindividually adjustable members for attracting the latter when thecurrent reaches a predetermined value.

12. In a circuit breaker having stationary and movable contact members,manually operable trip-free mechanism for effecting engagement anddisengagement of said contacts, automatically operable means associatedwith said mechanism for actuating the latter to disengage said contacts,comprising a trip device including a latching member normally releasablyconnected operatively with a part of said mechanism and releasable fromsaid part upon actuation of said trip device to disengage said contacts,thermal control means for actuating said latching mem' ber directly torelease said part of said mechanism, and magnetic control means foractuating said latching member directly to release said part of saidmechanism, said thermal control means and said magnetic control meansbeing individually adiustable independently of each other forcalibrating the circuit breaker for automatic operations in response todifferent current values under the control of said thermal means andsaid magnetic means, respectively.

13. In a circuit breaker, a stationary contact member, a movable contactmember engageable with and disengageable from said stationary contactmember, mechanism for operating said movable contact member to engageand disengage said stationary contact member, said mechanism including alink member, means mounting said movable contact member directly on saidlink in pivotal relation thereto whereby said movable contact member isbodily movable directly with said link member when said mechanism isactuated for said operation of said movable contact member and springmeans engaging directly said link and said movable contact member forresiliently moving said movable contact member directly in relation tosaid link for providing contact pressure when said movable contactmember engages said stationary contact member.

14. In a circuit breaker, a stationary contact member, a movable contactmember engageable with and disengageable from said stationary contactmember, mechanism for operating said movable contact member to engageand disengage said stationary contact member, said mechanism including alink member, means mounting said movable contact member directly on saidlink in pivotal relation thereto whereby said movable contact member isbodily movable directly with said link member when said mechanism isactuated for said operation of said movable contact member, and springmeans engaging directly said link and said movable contact member forresiliently moving said movable contact member directly in relation tosaid link for providing contact pressure when said movable contactmember engages said stationary contact member, said link member havinglaterally spaced side arms between which said movable contact member ispositioned, spring means being disposed between said side arms and saidmovable contact member having an end portion against which said springmeans exerts pressure for said resilient movement of said movablecontact member in relation to said link.

15. In a circuit breaker having stationary and movable contact members,mechanism for actuating said movable contact member to open and closethe circuit breaker, and a trip device including a, pivoted trip barhaving an arm provided with a latching member for releasably holdingsaid mechanism in contact-closing condition, said bar having a secondarm for pivotally moving said trip bar to move said latching member tomechanism-releasing position, and electromagnetic means for moving saidsecond arm to effect said movement of the trip bar, said magl4 neticmeans comprising a magnetic yoke and a companion armature, meansmounting said armature on said second arm for attraction by said yokewhen the latter is energized, said mounting means having provision foradjusting said armature in relation to said yoke for adjustably varyingthe air gap between said yoke and said armature.

THOMAS M. COLE.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,325,717 Swingle Aug. 3, 1943 2,573,306 Casey Oct. 30, 19512,573,307 Casey Oct. 30, 1951

